Red square in first schema remained from the drawing program "Xmind". This connection does not exist. Sorry if I misled you. All subsequent tests are conducted between two mikrotiks with default configuration.

Corrected first scheme

Hello, thank for help. There is only one default bridge1 on each mkt [admin@MKT-G.1 (CAM Primary)] > /interface bridge print Flags: X - disabled, R - running 0 R name="bridge1" mtu=auto actual-mtu=1500 l2mtu=1592 arp=enabled arp-timeout=auto mac-address=:C2 protocol-mode=rstp fast-forward=...

Hello, I installed two new CRS-328 without any vlans and firewall rules. They connected by "SFP+ direct attach cable (S+DA0001)" too.The result is the same ~ 800 Mbps. I can test only through "Mikrotik Btest tool" for it now. But I think iperf will give the same result as it was ...

Test on first image by iperf.

Thank you.

[admin@MKT-B.1 (Primary 192.168.88.1)] /interface bridge> port print Flags: X - disabled, I - inactive, D - dynamic, H - hw-offload # INTERFACE BRIDGE HW PVID PRIORITY PATH-COST INTERNAL-PATH-COST HORIZON 0 H ;;; defconf sfp-sfpplus12 bridge yes 1 0x80 10 10 none [admin@MKT-B.2 (Secondary 192.168.88...

Thank you!

>> Is it true that two CRS317-1G-16S+RM devices are involved in this test?
yes

>> Why not testing on a single device first? >>
/ip route print
/ip address print

Hello, we have problem with 10G speed when to connect CRS317-1G-16S+RM by SFP+ direct attach cable (S+DA0001 or S+DA0003). We have ~ 1.34 Gbits/sec. We have tried swith off "Auto Neogation" but it did not help. Server1 to Server2 connecting by SFP+ cable gives true speed 10.9 GBytes. Conne...